Polar Heart Montior calories burned is WRONG

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  • kateva143
    kateva143 Posts: 46 Member
    MFP and other calcs usually over estimate quite a bit. i use an FT7 as well, and usually even shave off a few calories from whatever it says at the end of my work out...so if I do a 335 cal workout I only put it in as 300. I figure I'm already getting added calories if I want to use them I shouldn't over -do it =/
  • 4lafz
    4lafz Posts: 1,078 Member
    I find my Polar is accurate and set up correctly. Have used it for two years. I find the MFP, other sites, and gym machine calories calculated WAY high. I am older and lighter - and def burned higher when I was larger. Anyway - I say go with the HRM numbers.
  • Azdak
    Azdak Posts: 8,281 Member
    Some factors to consider:

    1. A significant part of the calorie estimate number is based on an estimate of your fitness level. That is independent of all the other setup data. The FT7 does not allow for manual entry of VO2 max, so I am not sure how it sets that level. But if the level is set too low, it will underestimate your calories.

    2. A simple answer could be that the strap came loose and you only got intermittent readings during the walk. Not enough to notice, but enough to affect the results. However, I believe you said you experience the same thing on gym equipment, so that might rule this out.

    3. It's more difficult to estimate your effort, since you were walking on varied terrain. At your weight, the calorie burn suggests an intensity of about 3.5 METs, which is the equivalent of walking about 3.4 mph on level ground. That's about a 17:30 per mile pace. You can use that as a rough gauge for comparison

    Bottom line, given you weight, avg HR, and the terrain you describe, I suspect the HRM numbers are off by 30% or more. And I suspect the issue is related to #1. Unfortunately, I can't give you any clear cut advice on how to troubleshoot the issues with the HRM.

    As another comparison, you can try walking on a treadmill for around 45 min. If you are on a commercial treadmill, the calorie readings from the treadmill will be pretty accurate. It's another way of "testing" the HRM. If the TM calorie numbers are substantially different from the HRM, then it is likely it's the HRM that's "off". (This doesn't work with running).
  • Azdak
    Azdak Posts: 8,281 Member
    I hike quite frequently too and I wear my Garmin and not my Polar for hikes but the numbers at the end are always lower then what I think they should be based on how I am feeling. When you wear it for other activities do you feel like you are getting a correct reading?

    When I hit the gym, the polar is also quite a bit off. I enter my stats at the gym on elliptical and treadmill. Their numbers are pretty close to the online calories burned. Also, the gym machines pick up my heart rate too from the polar signal so that is also constantly monitored by the machine. not sure if the machines take the heart rate into account for the calories burned, but I guess they do.

    No, they don't. First of all, they don't have to because the machines are measuring the actual work you are doing, and aerobic intensities have a relatively fixed energy cost. So HR is irrelevant. (However, ellipticals use inaccurate equations to translate the "work" into calories, and the treadmill running equations have been shown to be about 15%-20% off as well),

    HRMs need heart rate because they have no idea what you are doing--they have to "guess".

    The heart rate display on a piece of equipment is separate from whatever chip they use to estimate calories. There is a separate Polar receiver that plugs into the console--it picks up the signal from your chest strap and displays it on the console.

    Cardio pieces do not use HR in their calculations--as I said, they don't have to.
  • amclaws25
    amclaws25 Posts: 128 Member
    This is why I don't eat back my calories, but if I do, its usually only half or so. There is just too much room for error.
  • babesintow
    babesintow Posts: 59
    I was told by a trainer that HRM can have up to a 20 % error rate based on your fitness level. The more experienced you are and the newer you are to exercise the higher the error rate. The people in the middle are the ones to have the numbers reflect the highest accuracy.

    I have a Garmin that I use with my Motoactv and I subtract 20% when I post, like many of us tracking our calories I would rather be under than over.

    I would also suggest checking the battery since you didn't say how old it is...the next time you use it check the watch while your working out to see if the HRM is still connected. Mine will tell me that it has disconnected if I am using my headphones.

    And MFP is highly inaccurate at times, I have never work out my stats with that equation I was afraid I goof something up.

    Maybe you can go to the store and get another one to compare and then return it????

    Good luck on your journey!!
  • Mrsbrandnewmeslimandtrim
    Mrsbrandnewmeslimandtrim Posts: 267 Member
    :drinker:
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